In standard LED lighting equipment, multiple LEDs are connected serially in a constant current
circuit. However, if any one of the LEDs has an open fault, all remaining LEDs go out as well. As a
conventional countermeasure for this, Zener diodes have been used, but issues of generating heat and power loss during breakdown had surfaced.

SIDAC “K1VZL series” offers a highly reliable protection function. They are triggered by a slight increase from breakover voltage VBO and immediately transition to an ON state. They also have low forward loss, allowing for a reduction of components installed for overheating protection.

Features
High reliability and improved efficiency while in the ON state (using bypass function) !
* 1/5 or less of the loss of Zener diodes.
Specification: Operating voltage VBO = 10V type (K1VZL09), 20 V type (K1VZL20)
Rated current IT = 500 mA (1A or higher is also possible depending on the mounting conditions)

[Basic characteristics]
● If the operating voltage is exceeded, it transitions to a low impedance (same as the forward direction of the diode)

[Comparison of power loss with Zener diode]

With the SIDAC “K1VZL” series, we were able to significantly reduce the heat generation and power loss that posed problems for LED failure prevention on LED lighting equipment. With raised environmental awareness, demand for LED lighting is expected to grow further. We are developing these diodes for traffic lights and emergency guide lights, where complete darkening is not acceptable, as well as street lights, building and submersible lighting where maintenance is difficult. Furthermore, we are also penetrating the automotive market where LED applications are also increasing.

The SIDAC “K1VZL” series will be displayed at the 10th “International Lighting Fair 2011” at Tokyo Big Sight for four days starting from March 8 (Tue.) to March 11 (Fri.), 2011. We invite you to please come and see us there.